The intention of the proposal is to save the digital image processing resources. However, the necessity to deal with hot and bad pixels in dark rows makes the invention so complex that its analog implementation advantages are in doubt:

Rambus application "Image sensor with a split-counter architecture" by Jie Shen proposes a way to reduce the data throughput problem in photon-counting pixel array. The idea is to locate only a small counter in each pixel and count an overflow signal outside of the array:

TSMC keeps working on various stacked sensor ideas. Two of the stacked sensor applications were published this week. One of them, the US20140035083, talks about raised photodiode with Tx gate structure, while ther rest of pixel transistors are located on the logic chip: "Elevated Photodiode with a Stacked Scheme" by Meng-Hsun Wan, Yi-Shin Chu, Szu-Ying Chen, Pao-Tung Chen, Jen-Cheng Liu, Dun-Nian Yaung.